The talent Overflowing Mists for Mistweaver works on NPC’s with high health. For example, I was able to outheal almost the entire Horde team on Fangraal in Ashran because Overflowing Mists was procing for 198k over and over again as he was hit.
That’s not a bug. It’s doing exactly what the tooltip says it does.
More an unintended interaction.
If it is intended, guess I’ll continue to out heal raids I guess.